Scientific Digest. Hearst Corporation.
Lua i Stíl Chicago (17ú heag.)Scientific Digest. US: Hearst Corporation.
Lua MLA (9ú heag.)Scientific Digest. Hearst Corporation.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
Lua APA (7ú heag.)